In the games

Tate and Liza run the Mossdeep City Gym. Both specialize in Psychic-type Pokémon and give out the Mind Badge once defeated. They also give TM04 (Calm Mind). The two of them engage in a Double Battle against the player when the player challenges them.

In the anime, Liza is depicted as being more experienced in battle, and it is implied in their debut episode that she always defeats Tate whenever the two have a battle. Liza loves to annoy Tate by teasingly reminding him of such things, but what angers Tate even more is Liza's habit of referring to him as her "little" brother even though they are twins. This is because Liza is actually the older twin. Nevertheless, Liza seems to care for Tate anyway.

When Ash Ketchum and his friends visited Mossdeep, Tate quickly befriended Max since they had quite a few things in common, including Max's issues with his own older sister, May. Said episode itself focuses primarily on Tate and Max, who spent nearly the entire time by themselves while having fun together. Likewise, Liza related with May, and took to showing her new friends around the facility.

Later, while Tate and Max were hanging out in the cockpit of the space shuttle, Team Rocket infiltrated the area with the intent of stealing the shuttle. Tate and Max were unaware of this until the trio reached the cockpit, whereupon Meowth tied the two boys up back-to-back with a rope. Fortunately, Ash's Corphish had been aboard the shuttle as well, and freed the duo, who promptly knocked the Rockets out. In the moments that followed, Tate and Max became the heroes of the day when they safely landed the shuttle. The Rockets then suffered the wrath of Liza and May, who attacked them with their Lunatone and Combusken, respectively, allowing Ash's Pikachu to send them flying.

In Solid as a Solrock, Tate and Liza finally faced of against Ash in a Double Battle, in which their Lunatone and Solrock, respectively, were up against Ash's Pikachu and Swellow. At first, they continuously argued with each other, which allowed their opponent to get hits in. However, after another attack by Team Rocket, the twins managed to work together. In the battle that followed, they showed an incredible ability to balance each other's Pokémon, becoming a seemingly unstoppable force that Ash had to resort to unorthodox tactics in order to defeat. Eventually, Pikachu and Swellow used Pikachu's Thunder attack as armor, and with this new-found power, they easily defeated Lunatone and Solrock, earning Ash the Mind Badge.

Pokémon

Liza's Lunatone is the Pokémon she uses in all Gym battles. When the twins battled each other in It's Still Rocket Roll to Me!, Lunatone won the battle for Liza. She later also used it against Team Rocket after they failed to steal a space shuttle from the Mossdeep Space Center.

At Mossdeep Gym

Baltoy (×4)

Tate and Liza's four Baltoy live at the Mossdeep Gym where, when Tate and Liza want a battle, they use Confusion to make a battlefield with zero gravity. When Team Rocket wanted to steal the space shuttle for the Boss, the Baltoy stopped the shuttle with Confusion.

In the manga

In the Pokémon Adventures manga

Liza and Tate are the guardians of Mt. Pyre. When they somehow sensed someone had intruded into Mt. Pyre, they went all the way to Lilycove from Mossdeep in order to protect the two Orbs. However, they fell into Mack's fire illusion until Juan rescued them. Afterwards, they become Ruby's and Sapphire's teachers in Double Battling on the Mirage Island. They stayed on the island to ensure Ruby and Sapphire can leave for Sootopolis safely, and were not seen since then.

Pokémon

This listing is for Tate and Liza's Pokémon in the Pokémon Adventures manga.

Lunatone

Lunatone was seen with Liza while she and Tate were traveling through a forest of Ghost Pokémon. It was used to help them find their way out. Lunatone was used against Mack and his illusionist skills. However, Mack was able to get the best of Lunatone.

Both Tate and Liza own a Spoink while on Mirage Island. They were used to assist Ruby and Sapphire on their training and battled Plusle and Minun. The cheering Pokémon were able to defeat the two Psychic-types. As a result, Sapphire earned herself a Badge from Tate and Liza.